Oeoeae checkley



' e. CHECKLEY PROPELLER Nov. 16 1926.

Filed Feb. 12, 1925 IN'VENTOR.

G CHECKLE Y BY 2 Z A TTORN E Y.

that the auxiliary I 1 Patented Nov. 16,1926.

'PATENT' .ononcn cnncxLnY, or new Y OBK,'1\T. Y.

OFFICE.

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Application filed February 1a, 1925. Serial No. 8,774..

7 This invention relates to propellers and has for-its object to increase the efiiciency of high speed propellers,',such as employed 7 on steamers, warships and motor boats, gen- Y i 'erally.

In the present type ofpropellers, it is well known that the greatestpower obtained by the propeller occurs at the ends ofthe blades nor in other words,ffurthest removed from 10 the propeller shaft. The surface of the propeller blade immediately 'adja-centthe shaft joperates in a dead center and practically no power is generated from this surface. It is j also well known that asuction vacuum exliists on the shaft and propeller blade surface,

due to the fact that the'pro eller is moved 7 Qfthrough the water with a egree of speed I greater than the-motion of the water, result- ,ing from its gravity or from its endeavor J i f" to; find a level and thevacuum of course,

tends to delay the rearward motion of the blade and retard theaction of the propeller. In, many instances, however, about one-half of the propeller blade is actually in contact with the water when the propeller is operating at a'hi'gh rate of speed and consequently it will be recognizedthat if a greater surface of the propeller blades is resented to the.water,'more power will be tained.

Various means have been resorted to in the pastto overcome'the objects such as by breaking up the vacuum that exists in front and in back of'the propeller blades and shaft, by making a hollow pro eller blade and by shunting the water in ifferent directions toward the end of the shaft so as to break up the existing vacuum.

My invention, relates to overcoming this problem by utilizing an auxiliary propeller, preferably in front of the main propeller in such manner that the water will be churned or directed immediately against the propeller blades at a point adjacent the inner ends thereof, or in other words, in and about the propeller shaft. It will be thus seen that the maximum surface of the main prospeller blades are utilized with the result that greater efliciency is obtained and more power generated. In actualpractice, I have found ropeller should be at least about one-half the size of the main propeller and located at a distance sufliciently close to the same without interfering with the o eration of the blades so that the water will directed toward the entire surface of the blades and throughout their entire length.

,In order to more fully understand and appreciate my invention, reference is had to the accompanying drawings, showing. a

preferred embodiment thereof, wherein:

Figure 1 is a front view of the main and auxiliary propellers, the propeller shaft being shown in section. 1

Figure 2 is a side view.

Referring now to the drawings, wherein like reference characters designate corresponding parts throughout the several views, I have shown a propeller consisting of three blades, although I do not desire to be limited or restricted to the exact number of blades because two, four or five blades may be utilized, ifiso desired. In the form- 'of the invention shown, 5 designates the propeller shaft and 6 a sleeve keyed thereto and secured on the end of the shaft by any suitable means such as a lock nut? and nut 8 as clearly shown by Figure 2' of the drawings. The blades 9 of the main pro eller may be of any desired shape and size, ing preferably disposed at an acute itch. Forwardly of the main propeller bIadesQ, the auxiliary propeller 10 is mounted, being spaced from the main propeller blades 9 so that they may operate together without interference, the propellerlO assisting and aid ing the operation of the main ropeller by churning the water whichwould otherwise engage thesurface of the main propeller at a point adjacent the surface of the shaft 5. The location of the propeller 10 breaks up .what might be regarded as the stream line of the water over that surface of the shaft and main propeller, which is a dead volume of water if the main propeller were operating under ordinary circumstances. The blades 10 of the auxiliary propeller drive the water against the entire surface of the blades of the main propeller and since the total surface of the blades are utilized, greater power results. In this manner, the engines or the power driven mechanism generate the greatest amount of power possible, which is otherwise lost because of the lack of resistance on that part of. the .pro eller-immediately adjacent the shaft. As s own, the auxiliary propeller is substantially one-half the size of the main propeller and is so spaced therefrom that the effect of the vacuum which ordinarily occurs at the surface of the shaft,

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is thus broken up.- Of course, the invention is further carried forth by mounting another propeller in. front of the auxiliary propeller 10, and one smaller in size, and in some instances,'an auxiliarypropeller may be mounted rearwardly of the main-propeller.

The main and auxiliary propellers may be cast with the sleeve 6 and mounted on the propeller shaft in the usual manner.

From the above description and objects set forth, a, propeller constructed in accordance with my invention will develop greater speed, produce the maximum efiiciency from the engineqin that an increased surface or resistance of the water is bad or in other words, a greater volume of water is agitated with the result that the maximum power obtainable is Secured. The power generated for driving the shaft depends, of course, on

the propeller surface and the results of the increased surface tends to greater efficiency. 'Having shown and described my invention, what I claim as'new and-desire to secure by United States Letters Patent is 1. A propeller shaft, a sleeve keyed to the shaft, 9. mam propeller carried by said sleeve. an auxiliary propeller carried by said sleeve located in front of the main propeller and substantially one-half the size of the main propeller, and the blades of the auxiliary pro eller being in alignment with those of t e main propeller.

2. A propeller shaft, a sleeve keyed to the shaft, a main propeller and an auxiliary propeller located immediately in front of the main propeller but spaced therefrom, both of said propellers being formed integral with said sleeve, and said auxiliary propeller. being substantially one-half the size of the main propeller whereby the volume of water may be agitated by the entire surface of the main propeller.

' In testimony whereof I aifix my signature.

GEORGE CHECKLEY. [re] 

